Multivoltage electric generator.



PATENTED DEOQ 1, 1903,

. G. .H. GIBSON.

' MULTIVOLTAGE ELECTRIC GENERATOR.

APPLICATION FILED APR. 4. 1903.

N MODEL.

WITIVESSES: INVENTOR NIT D STATES Patented December 1, 1 903.

PATENT OFFICE.

GEORGE H. GIBSON, OF HYDEPARK, MASSACHUSETTS, ASSIGNCR TC WESTINGHOUSEELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

MULTIVOLTAGE ELECTRIC GENERATOR.

SPECIFICATION forming part of Letters Patent N 0. 745,594, datedDecember 1, 1903'.

' Application filed April 4, 1903. Serial No. 151,199. (No model.)

To all whom it may concern:

Be it known that I, GEORGE H. GIBSON, a citizen of the United States,and a resident of I-Iydepark, in the county of Suffolk and State ofMassachusetts, have invented a new and useful Improvement inMultivoltage Electric Generators, of which the following is aspecification.

My invention relates to electric generators which provide a plurality ofdifferent voltages for the operation of translating devices; and it hasfor its object to provide a machine of comparatively simple andinexpensive construction from which may be derived a considerable numberof voltages of wide range in such manner that the circuits correspondingto the different voltages may be utilized either independently at thesame or at different times or conjointly in any order and manner thatmay be desired without disturbing the operation and regulation of thegenerator.

My invention is primarily based upon that covered by Patent No. 513,006,granted January 16, 1894:, to Michael von Dolivo-Dobrowolsky, in which abalancing or neutral conductor, between which and the main conductorsthe voltage is one-half that across the main conductors, is connected tothe middle point of a balancing-coil and the terminals of such coil areconnected across the armaturewinding of the generator.

In the simplest form of myinvention,which I have illustrated in theaccompanying drawings, the generator is shown partially in sideelevation and partially in section in Figure 1, Fig. 2 being adiagrammatic representation of the circuits of the machine.

As here illustrated, the machine comprises a suitable frame 1, having afield-magnet yoke 2, provided with pole-pieces 3 and excitingcoils 4 andalso with bearing-supports 5 for the shaft 6, all as is usual in thisclass of machines.

Mounted upon the shaft 6 and suitably keyed or otherwise fastenedthereto are an armature-spider 7, two sets of collectonrings 8 and 9,and two commutatoncylinders 10 and 11, a set of brushes 12 beingprovided and suitably supported for making engagement with therespective rings of the set 8 and a similar set of brushes 13 beingprovided for making engagement with the collector-rings of the set 9.Commutator-brushes 14 and 15 are also provided for engagement with thebars of the commutator-cylinder 10, and similar brushes 16 and 17 areprovided for engagement with the bars of the commutatorcylinder 11.

Two armature-windings 18 and 19, which may be located either in the sameor in different slots in the armature-core, are connected, respectively,to the commutator 10 and the commutator 11 and also to the sets ofcollector-rings 8 and 9.

Two balancing-coils 20 and 21 are provided, to the middle points of bothof which is connected the neutral conductor 22 of thedistributing-circuit, the other conductors 23, 24, 25, and 26 of saidcircuit being respectively connected to the brushes let, 17, 16, and 15of the commutators 10 and 11.

The outer terminals of the balancing-coils 20 and 21 may be respectivelyconnected to the brushes 12 of the collector-rings S, and intermediatepoints 20 and 21 of the said balancing-coils may be connected to thebrushes 13 of the rings 9, the last-named points of connection of thebalancing-coils being so selected that the length of winding betweeneach of these points and the middle point bears the same ratio to thelength of winding between the outer terminal of the coil and the middlepoint that the length of the winding 19 bears to that of the winding 18.

The employment of collectorrings and brushes in substantially the mannerabove indicated is obviously necessary in cases Where thebalancing-coils are stationary; but if the coils are mounted upon thearmaturespider or its shaft, so as to rotate therewith, directconnections with the armature-windings 18 and 19 may be made, asindicated in Fig. 2, and in view of the well-known char actor of thecircuit connections first above mentioned the diagrammatic illustrationin Fig. 2 may be regarded as indicative of each arrangement.

Two sets of balancing-coils might be employed in such manner that eacharmature Winding should have its own coils; but by employing the coilsas indicated the apparatus is simplified and serves the same purpose.

It will be observed that each branch of each balancing-coil is connectedto points in the high-voltage and low-voltage armature-windings that arealways in phase. It will be also understood that instead of providing asingle armature core with the two sets of coils separate cores may beutilized.

As here illustrated, the two armature-windings have ratio of one tofourthat is, the low-voltage winding 19 has twelve coils and thehigh-voltage winding 18 has forty-eight coils, the former having sixturns between brushes and the latter having twenty-four turns betweenbrushes. The same ratio obtains between the number of turns in anybalancing-coil from the neutral point to the point of connection of thelow-voltage armature-winding and from the neutral point to the point of.connection of the high-voltage armature-winding, these lengths beinghere indicated as two and eight-turns, respectively.

By providing a proper ratio of voltages between the two coils a largevariety of voltages may be secured from the external circuit. Forexample, if the voltage generated by the lowvoltage armature-winding isfifty and and that by the high-voltage armature-winding is two hundredthe voltage between conductors 22 and 2-1 will be twenty-five, thatbetween conductors 24E and 25 will be fifty, that between conductors 23and 24 will be seventy-five, that between conductors 22 and 23 will beone hundred, that between conductors 23 and 25 will be one hundred andtwenty-five, and that between conductors 23 and 26 will be two hundred.

Other simple ratios may be employed which will give diiferent ranges ofvoltages from four to SlX in number, according to the ratios of thevoltages to armaturewindings.

It the arniature-windings were applied to separate cores or were notplaced in slots, more complex ratios might be provided which would givedifferent ranges of voltage in the external circuit, and a greaternumber of armature-windings and corresponding commutators would give astill greater range of voltages for the operation of translatingdevices. Any increase in the number of armature-windings and commutators would, however, materially increase the complication, and hencewould not be so desirable as the number here indicated. It would also bepossible to employ two sets of balancing-coils in connection with twothree-wire generators of dilferent voltages,and thus secure the samerange of voltages that is here provided; but such a combination would bemore expensive and for that reason less desirable than a single machinehaving two armature-windings.

I claim as my invention 1. In a multivoltagegenerator, the combinationwith a plurality of armature-windiugs of different lengths, of aplurality of balancing-coils having their middle points connected to theneutral or balancing conductor of the external circuit and having theirouter terminals and certain intermediate points connected to thearmature-windings.

2. In a multivoltage system, the combination withdistributing-00nductors, of a generator having a plurality ofarmature-windings of different lengths having a definite voltage ratioand a plurality of balancing coils the middle points of which areconnected'to the neutral distributing-conductor, the outer terminals ofwhich are connected to equidistant points in the high-voltagearmature-windingandintermediate points ot'which are connected toequidistant points in the lowvoltage armature-winding.

3. In a multivoltage system, the combination withdistrihutirig-conductors, of a generator having a plurality ofarmature-windings adapted for different voltages and a plurality ofbalancing-coils connected at their middle points to the neutraldistributing-eonductor, at their outer terminals to equidistant pointsin the high-voltage armaturewinding and at intermediate points to thelow-voltage armature-winding, the lengths between the intermediatepoints of connection and the middle points of the balancing coilsbearing the same ratio to one-half the entire lengths of the coils thatthe low-voltage armaturewinding bears to the high-voltagearmature-winding.

4c. In a multivoltage system of distribution, the combination withdistributing-conductors, of two armature-windings having a definitevoltage ratio and two commutators to which all but one of thedistributing-conductors are connected and two balancingcoils havingtheir outer terminals connected to equidistant points in thehigh-voltage winding, their middle points connected to the neutralconductor of the distributing-circuit and having intermediate pointsconnected to the low-voltage armature-winding, the ratio betweenone-half the length of each coil and the length between the low-voltagearmature connection and the neutral-conductor connection being the sameas that of the highvoltage to the low-voltage armature-winding.

5. In a multivoltage generating and distributing system, the combinationwith two armature-windings of different voltage and separate commutatorsfor said windings, of two balancing-coils having their outer terminalsconnected to equidistant points in the high-voltage armature-winding andintermediate points connected to equidistant points in the low-voltagearmature-winding and five distributing-conductors two of which areconnected to one commutator and two to the other and one of which isconnected to the middle points of the two balancing-coils.

6. In a multivoltage generating and distributing system, the combinationwith two armature-windings of difierent voltage and independentcommutators to which said windings are connected, of two balancing-coilshaving their outer terminals connected to the high-voltage Winding andhaving intermediate points connected to points in the lowvoltage windingwhich are in phase with the points of connection in the high-voltagewinding and five distributing-conductors two of which are connected toone commutator and two to the other and the fifth of which is connectedto the middle points of the balancingcoils.

7. In a multivoltage system of generation and distribution, a singlegenerator comprising one field-magnet, two armature-windings, twocommutators and two balancing-coils in combination withdistributing-00nductors so connected to said commutators andbalancing-coils as to provide six voltages.

S. In a mnltivoltage generating and distributing system, the combinationwith two armature-windings having a definite voltage ratio and twobalancing-conductors each provided with leads which divide it so as toprovide lengths having a ratio corresponding to that of thearmature-windings, connections between equidistant points in saidarmaturewindings and the balancing-coil leads and fivedistributing-conductors two ,of which are connected to the high-voltagearmature-winding and two to the low-voltage armaturewiuding and thefifth of which is connected to the middle points of bothbalancing-coils.

In testimony whereof I have hereunto subscribed my name this 30th day ofMarch, 1903.

GEO. H: GIBSON.

Witnesses:

EARNEST T. CHILD, R. R. SMART.

